#!/usr/bin/env node
// discover-new-urls.mjs — Find relevant Microsoft Learn pages not yet in the registry.
// Scans sitemaps for URLs matching relevance patterns, suggests skill/category mapping.
// Usage: node discover-new-urls.mjs [--limit N]

import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { normalizeUrl } from './lib/url-normalize.mjs';
import { loadRegistry, saveReport } from './lib/registry-io.mjs';
import { streamSitemap, fetchSitemapIndex } from './lib/sitemap-stream.mjs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const DATA_DIR = join(__dirname, 'data');
const limitArg = process.argv.indexOf('--limit');
const limit = limitArg !== -1 ? parseInt(process.argv[limitArg + 1], 10) : Infinity;

// Relevance patterns — URL paths that indicate content this plugin should cover
const INCLUDE = [
  { pattern: /\/azure\/ai-foundry\//, skill: 'ms-ai-engineering', category: 'azure-ai-services' },
  { pattern: /\/azure\/ai-services\//, skill: 'ms-ai-engineering', category: 'azure-ai-services' },
  { pattern: /\/azure\/machine-learning\//, skill: 'ms-ai-engineering', category: 'mlops-genaiops' },
  { pattern: /\/azure\/search\//, skill: 'ms-ai-engineering', category: 'rag-architecture' },
  { pattern: /\/azure\/api-management\//, skill: 'ms-ai-engineering', category: 'api-management' },
  { pattern: /\/azure\/azure-monitor\//, skill: 'ms-ai-governance', category: 'monitoring-observability' },
  { pattern: /\/azure\/well-architected\//, skill: 'ms-ai-advisor', category: 'architecture' },
  { pattern: /\/microsoft-copilot-studio\//, skill: 'ms-ai-advisor', category: 'copilot-extensibility' },
  { pattern: /\/copilot\/microsoft-365\//, skill: 'ms-ai-advisor', category: 'copilot-extensibility' },
  { pattern: /\/microsoft-365-copilot\//, skill: 'ms-ai-advisor', category: 'copilot-extensibility' },
  { pattern: /\/security\/(?:ai|benchmark|engineering)\//, skill: 'ms-ai-security', category: 'ai-security-engineering' },
  { pattern: /\/azure\/defender-for-cloud\//, skill: 'ms-ai-security', category: 'ai-security-engineering' },
  { pattern: /\/purview\//, skill: 'ms-ai-governance', category: 'responsible-ai' },
  { pattern: /\/semantic-kernel\//, skill: 'ms-ai-engineering', category: 'agent-orchestration' },
  { pattern: /\/agent-framework\//, skill: 'ms-ai-engineering', category: 'agent-orchestration' },
  { pattern: /\/fabric\/(?:data-engineering|data-science|real-time-intelligence)\//, skill: 'ms-ai-engineering', category: 'data-engineering' },
  { pattern: /\/azure\/cosmos-db\//, skill: 'ms-ai-engineering', category: 'data-engineering' },
  { pattern: /\/azure\/databricks\//, skill: 'ms-ai-engineering', category: 'data-engineering' },
  { pattern: /\/entra\/(?:identity|agent)\//, skill: 'ms-ai-security', category: 'ai-security-engineering' },
];

// Exclude patterns — skip even if they match INCLUDE
const EXCLUDE = [
  /\/training\//,
  /\/credentials\//,
  /\/legal\//,
  /\/previous-versions\//,
  /\/archive\//,
  /\/samples\//,
  /\/release-notes?\//,
  /\/whats-new/,
  /\/changelog/,
  /\/migrate\//,
];

function classifyUrl(url) {
  if (EXCLUDE.some(p => p.test(url))) return null;
  for (const rule of INCLUDE) {
    if (rule.pattern.test(url)) {
      return { skill: rule.skill, category: rule.category };
    }
  }
  return null;
}

// Target sitemaps for discovery — same as poller, minus dotnet
const TARGET_PREFIXES = [
  'azure_en-us_',
  'microsoft-copilot-studio_en-us_',
  'security_en-us_',
  'fabric_en-us_',
  'power-platform_en-us_',
  'ai_en-us_',
  'copilot_en-us_',
  'compliance_en-us_',
  'agent-framework_en-us_',
  'semantic-kernel_en-us_',
  'entra_en-us_',
  'purview_en-us_',
];

function extractChildName(loc) {
  const match = loc.match(/\/_sitemaps\/([^/]+)\.xml$/);
  return match ? match[1] : null;
}

// --- Main ---
async function main() {
  const registry = loadRegistry(DATA_DIR);
  const knownUrls = new Set(Object.keys(registry.urls));
  console.log(`Registry: ${knownUrls.size} known URLs`);

  console.log('Fetching sitemap index...');
  const indexEntries = await fetchSitemapIndex();

  const targetChildren = indexEntries
    .filter(e => {
      const name = extractChildName(e.loc);
      return name && TARGET_PREFIXES.some(p => name.startsWith(p));
    });

  console.log(`Scanning ${targetChildren.length} sitemaps for new relevant URLs...`);

  const candidates = [];
  const bySkill = {};

  for (const child of targetChildren) {
    const childName = extractChildName(child.loc);
    let foundInChild = 0;

    try {
      for await (const entry of streamSitemap(child.loc)) {
        const normalized = normalizeUrl(entry.loc);
        if (!normalized || knownUrls.has(normalized)) continue;

        const classification = classifyUrl(normalized);
        if (!classification) continue;

        candidates.push({
          url: normalized,
          lastmod: entry.lastmod,
          sitemap: childName,
          suggested_skill: classification.skill,
          suggested_category: classification.category,
        });
        knownUrls.add(normalized); // Prevent dupes across sitemaps

        bySkill[classification.skill] = (bySkill[classification.skill] || 0) + 1;
        foundInChild++;

        if (candidates.length >= limit) break;
      }
    } catch (err) {
      console.error(`  ERROR scanning ${childName}: ${err.message}`);
    }

    if (foundInChild > 0) {
      console.log(`  ${childName}: ${foundInChild} new candidates`);
    }
    if (candidates.length >= limit) break;
  }

  // Sort by lastmod descending (newest first)
  candidates.sort((a, b) => (b.lastmod || '').localeCompare(a.lastmod || ''));

  const report = {
    generated_at: new Date().toISOString().split('T')[0],
    new_candidates: candidates.length,
    by_suggested_skill: bySkill,
    candidates,
  };

  saveReport('discovery-report.json', report, DATA_DIR);

  console.log(`\n=== Discovery Report ===`);
  console.log(`New relevant URLs found: ${candidates.length}`);
  console.log('By skill:', JSON.stringify(bySkill, null, 2));
  if (candidates.length > 0) {
    console.log('\nNewest 10:');
    for (const c of candidates.slice(0, 10)) {
      console.log(`  [${c.suggested_skill}/${c.suggested_category}] ${c.url}`);
      console.log(`    lastmod: ${c.lastmod}`);
    }
  }
}

main().catch(err => {
  console.error('Fatal error:', err.message);
  process.exit(1);
});